银杏叶提取物(EGb761)阻断AFB1致大鼠肝癌及其机制研究

Ginkgo biloba Extracts(EGb761) Inhibits Aflatoxin B_1-induced Hepatocarcinogenesis in Wistar Rats

目的:研究银杏叶提取物(EGb761)对黄曲霉素B1(AFB1)致大鼠肝细胞癌(HCC)发生发展的干预效果及其抗氧化作用。方法:实验大鼠按体质量随机分成3组:A组(AFB1组)、B组(AFB1+EGb761组)和C组(对照组)。分别于实验第14、28、42、55周进行肝活检并于第64周全部处死,观察大鼠肝脏癌前病变(γ-GT灶)、组织病理学及肝组织GSH-Px及MDA的变化。结果:在癌前期,第42及第55周时,B组单个γ-GT阳性灶的面积及灶总面积均显著小于相应时段A组的各项指标(P=0.000);动态观察定期肝脏活检的组织显示B组大鼠诱癌各时期肝脏损害均较A组轻,增生性病变发生亦较迟,HCC诱发率(26.92%)明显低于A组(76%)(P=0.000),对照组无肿瘤发生;B组GSH-Px活力较A组升高,而MDA含量较A组降低(P<0.05)。结论:EGb761能明显抑制AFB1诱发大鼠肝的癌前病变及延迟癌前病变向癌发展,这可能与其提高机体的抗氧化能力有关。

Objective： To investigate the effect of Ginkgo biloba extracts （ EGb761 ） on aflatoxin B1 （ AFB1 ） -induced hepatocarcinogenesis and its antioxidant activity in Wistar rats. Methods： 71 Wistar rats were randomly divided into three groups： AFB1 （group A） ; AFB1 ＋ EGb761 （group B）, Control（ group C）. Rats in gurop A and B were injected with AFB, through abdomen and the doses were 100-200 μg/kg, one to three times a week. Liver biopsy were performed in all rats during 14^thw, 28^thw, 42^thw and 55^thw, and were executed at 64^thw. Gammaglutamyl transpeptidase-positive hyperplastic cell foci （γ-GT foci） and histopathology of the liver tissue were observed. The levels of malondialdehyde （MDA）, as well as the activity of Glutathione peroxidase（GSH-Px） was examined. Results： At 42^thw and 55^thw, the γ-GT focus area（mm^2/focus） and general area of foci （mm^2/cm^2） of group B were significantly smaller than that in group A （P = 0. 000）. The incidence of hepatocelluiar carcinoma （HCC） in group B （26. 92% ）was significantly lower than that in group A （76%） （P = 0. 000）. Group C didnt have HCC development. EGb 761 markedly increased GSH-Px activity, reduced MDA levels（ P 〈 0. 05）. Conclusion： EGB761 shows effective inhibition to hepatocarcinogenesis induced by AFB1 in rats, which may be related to its antioxidant acctivity.